The African Union is holding a donor conference to raise funds for the millions needing food aid in the drought and famine-stricken Horn of Africa.

Leaders from Somalia, Djibouti and Ethiopia were among the first heads of state to arrive for the conference in Ethiopia's capital, Addis Ababa. Former Ghanaian president Jerry Rawlings, who is the AU envoy to Somalia, is also present.

As many as a dozen African leaders were expected for a meeting that was initially scheduled for early August. It was postponed due to what officials said were scheduling conflicts.

Slow response

The 54-member African Union, which has so far pledged only $500,000 in aid, has been strongly criticized for its slow response to the crisis.

Last week, a senior U.N. official said the conference hopes to raise $600 million. The United Nations says $2.5 billion of overall aid is needed to combat the famine.

Earlier, European Union foreign policy chief Catherine Ashton urged the African Union and international community to meet what she called their "moral obligation" to combat the drought, which is the Horn of Africa's most dire in 60 years.

The EU said it has increased its yearly humanitarian commitment from $140 million to $228 million, and that its member states have contributed an additional $630 million.

On Wednesday, Kanayo Nwanze, the head of the U.N. International Fund for Agricultural Development, welcomed the donor meeting, saying "Africa should not wait for the international community to solve its problems."

Earlier this month, the Organization of the Islamic Conference pledged $350 million to help combat the crisis. The United States has also pledged more than $500 million in food aid and refugee assistance.

International response

Meanwhile, U.N. Deputy Secretary General Asha-Rose Migiro says the international response to the crisis is accelerating, despite restrictions and security concerns in some parts of Somalia, where al-Qaida linked militants had prevented aid groups from distributing aid to millions in need.

U.N. agencies have increased their aid shipments to Somalia since militant group al-Shabab pulled its fighters out of the capital, Mogadishu, on August 6.

The U.N. has declared a famine in five regions of southern Somalia and predicts it will spread throughout the entire south of the country by the end of next month. The extreme drought has also affected parts of Kenya, Ethiopia and Djibouti.